1. Field of the Invention
The present invention relates to mowers used for mulching vegetation such as grass as it is being mowed. More particularly, the invention relates to a fastener assembly for attaching a removable mulch insert to a mower deck for quickly and easily converting the mower deck between discharge/collection and mulching operation modes.
2. Description of Related Art
Conventional discharge/collection mowers typically include a mower housing or deck for enclosing one or more rotating cutter blades. Discharge outlets have been provided in these conventional housings for allowing grass clippings to be ejected from the housing. The outlet also allows air to be discharged from the housing, thereby allowing the rotating blade to create a vacuum effect that lifts the grass within the housing so that it can be cut properly and evenly. The clippings ejected from the discharge outlet are then blown on top of the mowed grass, or collected by use of a bagging attachment coupled to the discharge outlet.
Mulching mowers are also known which enclose the area of the mower housing where the discharge outlet would be located in a conventional mower. These mowers often include modifications to the underside of the housing such as deflector surfaces for deflecting the clippings forwardly, downwardly and/or inwardly toward the center support for the blade so that the clippings will be re-cut. The use of such a mulching mower is advantageous where it is desirable to mulch or chop the grass clippings into fine particles and direct these clippings downwardly into the growing grass. This allows the grass clippings to be hidden beneath the top surface of a lawn. In addition, this allows the grass clippings to decompose on the soil where they are of nutritional value to growing vegetation.
In order to accommodate operators who wish to mulch clippings under some conditions and collect or discharge clippings in other circumstances, mulch inserts have been developed for installation in mower housings otherwise set up for discharge or collection. An insert of this type may be secured to the underside of a mower housing to effectively block off discharge outlet and to change the effective shape of the housing so that a chamber for each cutting blade is created, the chamber made up of deflector surfaces for deflecting the clippings forwardly, downwardly and/or inwardly toward the center support for the blade so that the clippings will be re-cut.
Adaptations may be made to these mulch inserts so that they may be easily and quickly installed and removed so that an operator may discharge/collect or mulch clippings, as desired, without undue delay and effort. For instance, in order to prevent a requirement that a fastening assembly, such as a nut and bolt, be engaged simultaneously on top of and on the underside of the deck, a portion of the assembly may be fixed to the mulch insert against rotation and axial movement so that, once the insert is positioned properly, the attachment may be completed, and the insert attached, by manipulation from above the deck. Such an adaptation is shown, for example, in U.S. Pat. No. 5,628,171, by Stewart, et al., the disclosure of which is hereby incorporated by reference.
However, where plastic or other composite inserts are utilized, it may be difficult to fix a fastener, particularly a standard bolt, to the insert against rotation due to a lack of precision in molding processes, and potentially also due to a lack of rigidity or durability of the composite material which the insert is made from.